Hey there, optometrists. In the March/April issue of Optometric Management, we're talking about how to monitor our intravitreal injection patients. These are our patients that are going to retina and getting injections in their vitreous cavity. And what we want to note are 2 things: 1. What type of medication are they having injected? Is it a steroid or is it an anti-VEGF medication?

What we found is that vascular endothelial growth factor actually plays a role in the regeneration of our corneal nerves, so our patients who are getting anti-VEGF injections have a harder time keeping their corneal nerves healed.

And then 2. we want to know how many injections they have had. In a 2023 study that was published in the journal Medicine, we found that 3 was the magic number.¹ If your patient had had 3 intravitreal injections, they were more at risk for developing neurotrophic keratitis than patients who had had less than 3 injections.

Once we know those 2 bits of information, we can start to monitor our patients more closely. We'll want to monitor these patients at least every 6 months, if not more closely, depending on how often they're having their intravitreal injections. When we see them in the clinic, let's do a symptom survey. What we're looking for is patients complaining about their vision decreasing. If the epithelium breaks down in the center, their vision will be affected.

We, of course, also want to assess corneal sensation: checking those corneal nerves and making sure they're not headed toward being neurotrophic. We can do that with a Cochet-Bonnet esthesiometer or a simple cotton wisp or dental floss, but use something to assess the sensitivity of the center of the cornea. Then we can employ some vital dye staining with our fluorescein to see if there's a central staining pattern that is quintessential for neurotrophic keratitis. We're not going to see the staining inferiorly like we do with keratitis sicca, but centrally with neurotrophic keratitis.

And then finally, you'll also want to evaluate the tear film and the cornea and conjunctiva, making sure there's no infection, that there's a robust tear lake, and using the tools in our toolbox to treat those as you see fit.

Monitoring our intravitreal injection patients more closely will be crucial to finding these early stages of neurotrophic keratitis.OM

References

1. Qi Y, Cui L, Zhang L, et al. Effect of repeated intravitreal anti-vascular endothelial growth factor drugs on corneal nerves. Medicine (Baltimore). 2023;102(29):e34210. doi:10.1097/MD.0000000000034210